In order to find antiviral compounds againstHerpes simplex virus type I (HSV-1) and II (HSV-2) from natural products, a convenient virus-induced cytopathic effect (CPE) inhibition assay was introduced. More than 300 fractions were prepared by solvent fractionation from sixty collected plants or purchased herbal medicines, and their anti-herpetic activities were evaluated. Among them, several medicinal plants showed potent anti-herpetic activity. Selective indexes (SI) of the EtOAc extract of Caraganae Radix (Caragana sinica) against HSV-1 and HSV-2 were more than 8.06 and 24.79, SI of the MeOH extract ofAcer okamotoanum leaves were 3.92 and 3.51, SI of the CH(2)Cl(2) extract of Veratri Rhizoma et Radix (Veratrum patulum) were 5.49 and 1.31 and SI of the MeOH extract of aerial part of Osmundae Rhizoma (Osmunda japonica) were more than 3.45 and 1.25, respectively.